Rabeprazole suppresses gastric acid secretion by inhibiting the gastric H⁺/K⁺-ATPase at the secretory surface of the gastric parietal cell. Because this enzyme is regarded as the acid (proton) pump within the parietal cell, Rabeprazole has been characterized as a gastric proton-pump inhibitor.

Rabeprazole Gastro-resistant tablets are indicated for the treatment of:

• Active duodenal ulcer
• Active benign gastric ulcer
• Symptomatic erosive or ulcerative gastro-esophageal reflux disease (GERD).
• Gastro-esophageal Reflux Disease Long-term Management (GERD Maintenance)
• Symptomatic treatment of moderate to very severe gastro-esophageal reflux disease (symptomatic GERD)
• Zollinger-Ellison Syndrome
• In combination with appropriate antibacterial therapeutic regimens for the eradication of Helicobacter pylori in patients with peptic ulcer disease.

Active Duodenal Ulcer and Active Benign Gastric Ulcer: The recommended oral dose for both bioactive duodenal ulcer and active benign gastric ulcer is 20 mg to be taken once daily in the morning. Most patients with active duodenal ulcer heal within four weeks. However, a few patients may require an additional four weeks of therapy to achieve healing. Most patients with active benign gastric ulcer heal within six weeks. However, again a few patients may require an additional six weeks of therapy to achieve healing.

Erosive or Ulcerative Gastro-Esophageal Reflux Disease (GERD): The recommended oral dose for this condition is 20 mg to be taken once daily for four to eight weeks.

Gastro-Esophageal Reflux Disease Long-term Management (GERD Maintenance): For long-term management, a maintenance dose of rabeprazole sodium 20 mg or 10 mg once daily can be used depending upon patient response.

Symptomatic treatment of moderate to very severe Gastro-Esophageal Reflux Disease (symptomatic GERD): 10 mg once daily in patients without oesophagitis. If symptom control has not been achieved during four weeks, the patient should be further investigated. Once symptoms have resolved, subsequent symptom control can be achieved using an on-demand regimen taking 10 mg once daily when needed.

Treatment of GERD in pediatric patients 1 to 11 years of age (Less than 15 kg): 5 mg once daily for 12 weeks with the option to increase to 10 mg if inadequate response.

Treatment of GERD in pediatric patients 1 to 11 years of age (15 kg or more): 10 mg once daily for 12 weeks. 

Zollinger-Ellison Syndrome: The recommended adult starting dose is 60 mg once a day. The dose may be titrated upwards to 120 mg/day based on individual patient needs. Single daily doses up to 100 mg/day may be given. 120 mg dose may require divided doses, 60 mg twice daily. Treatment should continue for as long as clinically indicated.

Eradication of H. pylori: Patients with H. pylori infection should be treated with eradication therapy. The following combination given for 7 days is recommended. Rabeprazole sodium 20 mg twice daily, clarithromycin 500 mg twice daily and amoxicillin 1g twice daily.

Administration

For indications requiring once-daily treatment Rabeprazole tablets should be taken in the morning, before eating; and although neither the time of day nor food intake was shown to have any effect on rabeprazole sodium activity, this regimen will facilitate treatment compliance. Patients should be cautioned that the Rabeprazole tablets should not be chewed or crushed, but should be swallowed whole.

Hypersensitivity to the active substance or to any of the excipients. Rabeprazole is contra-indicated in pregnancy and during breastfeeding.

In general, Rabeprazole is well-tolerated in both short-term and long-term studies. Rabeprazole may sometimes cause headache, diarrhoea, abdominal pain, vomiting, constipation, dry mouth, increased or decreased appetite, muscle pain, drowsiness, dizziness.

Overdose Effects

The maximum established exposure has not exceeded 60 mg twice daily, or 160 mg once daily. Effects are generally minimal, representative of the known adverse event profile and reversible without further medical intervention. No specific antidote is known. Rabeprazole is extensively protein bound and is, therefore, not dialysable. As in any case of overdose, treatment should be symptomatic and general supportive measures should be utilised.

• Symptomatic response to therapy with Rabeprazole does not preclude the presence of gastric or oesophageal malignancy, therefore the possibility of malignancy should be excluded prior to commencing treatment with Rabeprazole 20 mg Gastro-resistant Tablets.
• Patients on long-term treatment (particularly those treated for more than a year) should be kept under regular surveillance.
• Proton pump inhibitors, especially if used in high doses and over long durations (>1 year), may modestly increase the risk of hip, wrist and spine fracture, predominantly in the elderly or in presence of other recognised risk factors. Observational studies suggest that proton pump inhibitors may increase the overall risk of fracture by 10–40%. Some of this increase may be due to other risk factors. Patients at risk of osteoporosis should receive care and they should have an adequate intake of vitamin D and calcium.
• A risk of cross-hypersensitivity reactions with other proton pump inhibitor or substituted benzimidazoles cannot be excluded.
• Patients should be cautioned that Rabeprazole gastro-resistant tablets should not be chewed or crushed, but should be swallowed whole.
• There have been post marketing reports of blood dyscrasias (thrombocytopenia and neutropenia). In the majority of cases where an alternative aetiology cannot be identified, the events were uncomplicated and resolved on discontinuation of rabeprazole.
• Hepatic enzyme abnormalities have been seen in clinical trials and have also been reported since market authorisation. In the majority of cases where an alternative aetiology cannot be identified, the events were uncomplicated and resolved on discontinuation of rabeprazole.
• No evidence of significant drug related safety problems was seen in a study of patients with mild to moderate hepatic impairment versus normal age and sex matched controls. However because there are no clinical data on the use of rabeprazole in the treatment of patients with severe hepatic dysfunction the prescriber is advised to exercise caution when treatment with Rabeprazole 20mg Gastro-resistant. Tablets is first initiated in such patients.
• Co-administration of atazanavir with Rabeprazole is not recommended.
• Treatment with proton pump inhibitors, including rabeprazole, may possibly increase the risk of gastrointestinal infections such as Salmonella, Campylobacter and Clostridium difficile.

Hypomagnesaemia: Severe hypomagnesaemia has been reported in patients treated with PPIs like rabeprazole for at least three months, and in most cases for a year. Serious manifestations of hypomagnesaemia such as fatigue, tetany, delirium, convulsions, dizziness and ventricular arrhythmia can occur but they may begin insidiously and be overlooked. In most affected patients, hypomagnesaemia improved after magnesium replacement and discontinuation of the PPI. For patients expected to be on prolonged treatment or who take PPIs with digoxin or drugs that may cause hypomagnesaemia (e.g., diuretics), health care professionals should consider measuring magnesium levels before starting PPI treatment and periodically during treatment.

Influence on vitamin B12 absorption: Rabeprazole sodium, as all acid-blocking medicines, may reduce the absorption of vitamin B12 (cyanocobalamin) due to hypo- or a- chlorhydria. This should be considered in patients with reduced body stores or risk factors for reduced vitamin B12 absorption on long-term therapy or if respective clinical symptoms are observed.

Subacute cutaneous lupus erythematosus (SCLE): Proton pump inhibitors are associated with very infrequent cases of SCLE. If lesions occur, especially in sun-exposed areas of the skin, and if accompanied by arthralgia, the patient should seek medical help promptly and the health care professional should consider stopping Rabeprazole. SCLE after previous treatment with a proton pump inhibitor may increase the risk of SCLE with other proton pump inhibitors.

Interference with laboratory tests: Increased Chromogranin A (CgA) level may interfere with investigations for neuroendocrine tumours. To avoid this interference, Rabeprazole 20mg Gastro-resistant Tablets treatment should be stopped for at least 5 days before CgA measurements. If CgA and gastrin levels have not returned to reference range after initial measurement, measurements should be repeated 14 days after cessation of proton pump inhibitor treatment.

Use in Special Populations

Renal and hepatic impairment: No dosage adjustment is necessary for patients with renal or hepatic impairment.

Pediatric populations: Rabeprazole is not recommended for use in children due to a lack of data on safety and efficacy.

Pregnancy & Lactation

US FDA pregnancy category 'C'. Studies have been performed in animals and have revealed no evidence of impaired fertility or harm to the fetus due to Rabeprazole. There are however, no adequate and well-controlled studies in pregnant women. Rabeprazole is likely to be excreted in human milk, a decision should be made whether to discontinue nursing or to discontinue the drug, taking into account the importance of the drug to the mother.